In two-way radio systems, a plurality of subscribers, each with an associated subscriber unit (SU), wirelessly communicate to infrastructure such as various Base Transceiver Stations (BTSs), repeaters, etc. Examples of the two-way radio systems can include European Telecommunications Standards Institute Digital Mobile Radio (ETSI-DMR), Terrestrial Trunked Radio (TETRA), Project 25 (P25), Land Mobile Radio (LMR), and the like. The SU is a mobile device that is configured to communicate in a two-way radio system, and the plurality of subscribers are each users with their associated SU.
In the two-way radio system, a call initiator, with an SU, can make a group call by requesting the group call for the specified subscribers or group. For example, the group call may be a group voice call and the specified subscribers may be members of a group, i.e. an assigned group of subscribers. Disadvantageously, in conventional group call situations, the group call is unconfirmed and it is not possible for the call initiator to determine if the group call has reached all of the subscribers associated with (e.g., subscribed to) the group. For example, the group call could fail to reach some or all of the associated subscribers for various reasons such as some of the subscribers are out of range or powered off, some of the subscribers are participating in other calls, some of the subscribers are disabled, etc.
Conventionally, there have been attempts to remedy these limitations. For example, in some two-way radio systems, a presence notification (PN) server is used to track whether or not SUs are in the system, i.e., presence information. This can be done via over-the-air (OTA) interfaces between the SUs and the PN server, and the PN server is aware of the presence of the SUs in the system. However, the PN server is only aware of whether or not the SUs are present somewhere in the system and cannot tell if a group call actually reaches a particular subscriber associated with the group. For example, the group call may not reach the particular subscriber for various reasons such as when the particular subscriber is already participating in another group or a separate private call.
Accordingly, there is a need for an improved method and apparatus for group call confirmation in two-way radio systems.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.